SF Bay Delta Protection

Chinook salmon in the shallows

Essential to California’s Financial and Environmental Future: a Healthy Delta

The San Francisco Bay Delta, a freshwater body formed where the Sacramento, San Joaquin and several smaller rivers meet, near the city of Stockton, is the largest natural estuary on the West Coast. It covers more than 1,100 square miles, an area about three times the size of the City of San Diego. It provides breeding grounds and habitat for a range of animals, including Chinook salmon and the endangered Delta smelt.

The Bay Delta's ecosystem has dramatically declined because of excessive water diversions, introduced nonnative invasive species, and water pollution.

Now the Bay Delta's future and function is threatened by a proposal to build a single tunnel that would divert millions of acre-feet of fresh water from above the Delta to parts below the estuary. Sierra Club California opposes the construction of the single tunnel project. Instead, we believe Californians should pursue a range of other strategies that together will sustainably meet water needs while protecting the environment.

Get Involved

If you want to join the Delta Tunnel Campaign, sign up below:


For any questions about the campaign, email Caty Wagner (caty.wagner@sierraclub.org) about the Delta Tunnel project in Southern California, or Molly Culton (molly.culton@sierraclub.org) in Northern California.
Everyone is welcome to join. You don't need to have previous advocacy experience or be familiar with the Bay-Delta Tunnel project. We're looking forward to meeting you!

SF Bay Delta Fact Sheets

Position Papers and Other Relevant Documents

CA Water Webinar Series

Stop the Delta Tunnel Series